This invention relates generally to ram air turbine assemblies, and more particularly to deicing systems for ram air turbine assemblies.
Air driven turbines are used to convert mechanical energy of passing air into other useful forms of energy. One such example for an air-driven turbine is a wind turbine that captures the energy of passing winds. The wind turbine, depending on the particular design, will directly or indirectly convert the energy of wind into electrical power.
Another example is the ram air turbine, which is deployed into a passing airstream from a moving body. Ram air turbines are well known in many fields, including as a supplementary or emergency power source for aircraft. For example, ram air turbines usually are coupled to one or more hydraulic pumps and/or electrical generators. They can be deployed automatically upon a predefined condition, such as upon loss of one or more main engines or generators that causes a loss of electrical power. Most turbines are also configured for manual deployment by the pilot or other crew member in the event that the automatic deployment signal is not received by the appropriate controller for releasing the turbine into the passing airstream.
Because of its nature, a ram air turbine on a particular aircraft is rarely if ever activated except during a real operational emergency. As such, additional measures are taken to ensure that the turbine is ready to be operated at a moment's notice. For example, such generators are prone to ice buildup in the air gap between the rotating assembly and the stationary assembly. This issue has previously been addressed by incorporating separate resistance heating elements. These elements and their circuitry add weight to an already rarely used device. As a separate system located close to the main stator windings of the ram air generator, they are not readily inspected or repaired without disassembly of the generator.